/*
 * Copyright (c) 2020, OpenCloudDB/MyCAT and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software;Designed and Developed mainly by many Chinese
 * opensource volunteers. you can redistribute it and/or modify it under the
 * terms of the GNU General Public License version 2 only, as published by the
 * Free Software Foundation.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Any questions about this component can be directed to it's project Web address
 * https://code.google.com/p/opencloudb/.
 *
 */
package io.mycat.manager.response;

import io.mycat.MycatServer;
import io.mycat.backend.mysql.PacketUtil;
import io.mycat.buffer.BufferPool;
import io.mycat.buffer.ByteBufferArena;
import io.mycat.buffer.DirectByteBufferPool;
import io.mycat.config.Fields;
import io.mycat.manager.ManagerConnection;
import io.mycat.net.NIOProcessor;
import io.mycat.net.mysql.EOFPacket;
import io.mycat.net.mysql.FieldPacket;
import io.mycat.net.mysql.ResultSetHeaderPacket;
import io.mycat.net.mysql.RowDataPacket;
import io.mycat.util.IntegerUtil;
import io.mycat.util.LongUtil;
import java.nio.ByteBuffer;

/**
 * 查看处理器状态
 *
 * @author mycat
 * @author mycat
 */
public final class ShowProcessor {

  private static final int FIELD_COUNT = 12;
  private static final ResultSetHeaderPacket header = PacketUtil.getHeader(FIELD_COUNT);
  private static final FieldPacket[] fields = new FieldPacket[FIELD_COUNT];
  private static final EOFPacket eof = new EOFPacket();

  static {
    int i = 0;
    byte packetId = 0;
    header.packetId = ++packetId;

    fields[i] = PacketUtil.getField("NAME", Fields.FIELD_TYPE_VAR_STRING);
    fields[i++].packetId = ++packetId;

    fields[i] = PacketUtil.getField("NET_IN", Fields.FIELD_TYPE_LONGLONG);
    fields[i++].packetId = ++packetId;

    fields[i] = PacketUtil.getField("NET_OUT", Fields.FIELD_TYPE_LONGLONG);
    fields[i++].packetId = ++packetId;

    fields[i] = PacketUtil.getField("REACT_COUNT", Fields.FIELD_TYPE_LONGLONG);
    fields[i++].packetId = ++packetId;

    fields[i] = PacketUtil.getField("R_QUEUE", Fields.FIELD_TYPE_LONG);
    fields[i++].packetId = ++packetId;

    fields[i] = PacketUtil.getField("W_QUEUE", Fields.FIELD_TYPE_LONG);
    fields[i++].packetId = ++packetId;

    fields[i] = PacketUtil.getField("FREE_BUFFER", Fields.FIELD_TYPE_LONGLONG);
    fields[i++].packetId = ++packetId;

    fields[i] = PacketUtil.getField("TOTAL_BUFFER", Fields.FIELD_TYPE_LONGLONG);
    fields[i++].packetId = ++packetId;

    fields[i] = PacketUtil.getField("BU_PERCENT", Fields.FIELD_TYPE_TINY);
    fields[i++].packetId = ++packetId;

    fields[i] = PacketUtil.getField("BU_WARNS", Fields.FIELD_TYPE_LONG);
    fields[i++].packetId = ++packetId;

    fields[i] = PacketUtil.getField("FC_COUNT", Fields.FIELD_TYPE_LONG);
    fields[i++].packetId = ++packetId;

    fields[i] = PacketUtil.getField("BC_COUNT", Fields.FIELD_TYPE_LONG);
    fields[i++].packetId = ++packetId;

    eof.packetId = ++packetId;
  }

  public static void execute(ManagerConnection c) {
    ByteBuffer buffer = c.allocate();

    // write header
    buffer = header.write(buffer, c, true);

    // write fields
    for (FieldPacket field : fields) {
      buffer = field.write(buffer, c, true);
    }

    // write eof
    buffer = eof.write(buffer, c, true);

    // write rows
    byte packetId = eof.packetId;
    for (NIOProcessor p : MycatServer.getInstance().getProcessors()) {
      RowDataPacket row = getRow(p, c.getCharset());
      row.packetId = ++packetId;
      buffer = row.write(buffer, c, true);
    }

    // write last eof
    EOFPacket lastEof = new EOFPacket();
    lastEof.packetId = ++packetId;
    buffer = lastEof.write(buffer, c, true);

    // write buffer
    c.write(buffer);
  }

  private static RowDataPacket getRow(NIOProcessor processor, String charset) {
    BufferPool pool = processor.getBufferPool();
    RowDataPacket row = new RowDataPacket(FIELD_COUNT);
    long bufferSize = 0;//总数
    long bufferCapacity = 0;//使用
    long free = 0;
    long bufferUsagePercent = 0;
    long bufferSharedOpts = pool.getSharedOptsCount();
    try {
      if (pool instanceof ByteBufferArena) {
        ByteBufferArena bufferPool = (ByteBufferArena) pool;
        bufferSize = bufferPool.size();//总大小
        bufferCapacity = bufferPool.capacity();//使用
        free = bufferSize - bufferCapacity;
        bufferUsagePercent = (long) ((bufferCapacity) * 100.0 / bufferSize);
      } else if (pool instanceof DirectByteBufferPool) {
        DirectByteBufferPool bufferPool = (DirectByteBufferPool) pool;
        bufferSize = bufferPool.size();//总大小
        bufferCapacity = bufferPool.getNetDirectMemoryUsage().values().stream()
            .mapToLong(i -> i).count();
        free = bufferSize - bufferCapacity;
        bufferSharedOpts = bufferPool.getSharedOptsCount();
        bufferUsagePercent = (long) ((bufferCapacity) * 100.0 / bufferSize);
      } else {
        return row;
      }
      row.add(processor.getName().getBytes());
      row.add(LongUtil.toBytes(processor.getNetInBytes()));
      row.add(LongUtil.toBytes(processor.getNetOutBytes()));
      row.add(LongUtil.toBytes(0));
      row.add(IntegerUtil.toBytes(0));
      row.add(IntegerUtil.toBytes(processor.getWriteQueueSize()));
      row.add(LongUtil.toBytes(free));
      row.add(LongUtil.toBytes(bufferSize));
      row.add(LongUtil.toBytes(bufferUsagePercent));
      row.add(LongUtil.toBytes(bufferSharedOpts));
      row.add(IntegerUtil.toBytes(processor.getFrontends().size()));
      row.add(IntegerUtil.toBytes(processor.getBackends().size()));
    } finally {
      return row;
    }
  }

}